Research on surrounding rock abrasivity and its influence factors in TBM tunnelling inclined shaft project

2020 ◽  
Author(s):  
Jinguo Cheng ◽  
Hua Jiang ◽  
Yusheng Jiang ◽  
Jingling Zhang
Keyword(s):  
Influence Factors ◽  
Surrounding Rock ◽  
Rock Abrasivity

scholarly journals Study and Application on Stability Classification of Tunnel Surrounding Rock Based on Uncertainty Measure Theory

2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Hujun He ◽  
Yumei Yan ◽  
Cuixia Qu ◽  
Yue Fan
Keyword(s):  
Measure Theory ◽  
Influence Factors ◽  
Surrounding Rock ◽  
Uncertainty Measure ◽  
In Situ Data ◽  
Rock Stability ◽  
Practical Engineering ◽  
Stability Classification ◽  
Recognition Criterion

Based on uncertainty measure theory, a stability classification and order-arranging model of surrounding rock was established. Considering the practical engineering geologic condition, 5 factors that influence surrounding rock stability were taken into account and uncertainty measure function was obtained based on the in situ data. In this model, uncertainty influence factors were analyzed quantitatively and qualitatively based on the real situation; the weight of index was given based on information entropy theory; surrounding rock stability level was judged based on credible degree recognition criterion; and surrounding rock was ordered based on order-arranging criterion. Furthermore, this model was employed to evaluate 5 sections surrounding rock in Dongshan tunnel of Huainan. The results show that uncertainty measure method is reasonable and can have significance for surrounding rock stability evaluation in the future.

Prediction of Instability and Mechanism of Multi-Factor Comprehensive Action on Mine Goaf

2014 ◽  
Vol 13 ◽  
pp. 39-48 ◽  
Author(s):  
Wei Jian Yu ◽  
Shao Hua Du ◽  
Wei Jun Wang
Keyword(s):  
Bp Neural Network ◽  
Engineering Geology ◽  
Influence Factors ◽  
Surrounding Rock ◽  
Engineering Properties ◽  
Engineering System ◽  
Iron Mine ◽  
Actual Change ◽  
Real Time Tracking ◽  
Function Matrix

In allusion to phenomenon of large instability of underground goaf, research is carried on prediction of instability and mechanism of multi-factor comprehensive action. Firstly, according to large number of examples of instability disaster in mines at home and abroad, influence factors of goaf stability was analyzed, including characteristics of surrounding rock, conditions of engineering geology, engineering properties, structure parameters of goaf and other artificial mining and time etc; then, using BP neural network to establish the comprehensive function matrix RSE, and putting forward a prediction index Fi, this index can be real-time tracking on the actual change conditions of surrounding rock scene in mining goaf, showing the comprehensive action results of each factor on steady state of underground goaf engineering system; finally, on the basis of 36 samples, the stable value and interval value of the corresponding multi-factor comprehensive action index Fi can be obtained after calculation by using comprehensive function matrix RSE. An actual example showed that, value of multi-factor comprehensive action index Fi was-0.8159 in goaf of an iron mine, which was in instability state.

scholarly journals Research on the Transmission of Stresses by Roof Cutting near Gob Rocks

Energies ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1237
Author(s):  
Zhibiao Guo ◽  
Haohao Wang ◽  
Zimin Ma ◽  
Pengfei Wang ◽  
Xiaohui Kuai ◽  
...  
Keyword(s):  
Early Stage ◽  
Pressure Coefficient ◽  
Influence Factors ◽  
Stress Transfer ◽  
Main Roof ◽  
Surrounding Rock ◽  
Pressure Relief ◽  
Rock Structure ◽  
Immediate Roof ◽  
The Stability

Pressure relief for roadways retained by roof cutting is essentially caused by stress transfer. In this paper, the stress transfer mechanism of 16011 tail entry with roof cutting in Zhaogu No.1 coal mine is studied from the following two aspects: the change of the tail entry surrounding the rock structure and the interaction between the roadway surrounding rock and supporting structures. It is found by numerical simulation that roof cutting can significantly reduce the magnitude of roadway roof stress, transferring the concentrated stress induced by excavation and mining away from the roadway, and forming an obvious triangle pressure relief area in front of the working face. In the early stage after mining, most of the overburden load is transferred downward through the immediate roof of the roadway. With the movement of overlying strata, the stress, initially transferred to the immediate roof strata, is gradually transferred to the gob, and the calculation formula and influence factors of the transferred stress are derived. In addition, through the establishment of the mechanical model and theoretical calculation of the key rock block of the main roof, the roadside support resistance required to ensure the stability of the main roof block is determined. The field monitoring shows that the lateral pressure coefficient of the roadside caved rocks is 0.36 and the constant resistance and large deformation anchor cable (CRLDAC) and the roadway temporary support play roles of conduction and control in the process of stress transfer, and effectively ensure the stability of surrounding rock during the service life of the retained gob-side entry by roof cutting (RGERC).

scholarly journals Structural Mechanical Characteristics and Instability Law of Roof Key Block Breaking in Gob-Side Roadway

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Xinfeng Wang ◽  
Mingyuan Lu ◽  
Yuhao Gao ◽  
Wenbo Luo ◽  
Wengang Liu
Keyword(s):  
Mechanical Characteristics ◽  
Influence Factors ◽  
Vertical Direction ◽  
Surrounding Rock ◽  
Fracture Line ◽  
Mechanical Transmission ◽  
Working Face ◽  
Before And After ◽  
Weak Rock Mass ◽  
Key Block

The influence of mining on the upper section of working face leads to the fracture of the lateral key block of the roof. From the goaf to the coal body, a group of “left-middle-right” key blocks are formed. According to the three different spatial position structure relations formed by roadway and broken key block in practical engineering, the mechanical causes of broken structure of key block in roof of roadway along goaf are analyzed. FLAC3D is used to simulate and analyze the deformation characteristics and stress state of key block structure model before and after roadway excavation, and the mechanical characteristics and instability mechanism of key block sliding and breaking under three spatial structure modes are obtained. With the help of the mathematical model of material mechanics, the structural mechanical behavior of key block model of roof before and after roadway excavation and the temporal and spatial evolution law of unloading and breaking are studied. The results show that the complex influence factors of mining disturbance and low strength of the weak rock mass will weaken the internal balance of “masonry beam” structure. When the roadway is located below the fracture line of the key block, the middle key block will rotate and lose stability with the side hinge joint of the goaf as the axis; when the roadway is located in the fracture line of the key block, it is easy for the middle key block to slide and lose stability; when the roadway is located outside the fracture line of the key block, the middle key block is in the state of complete collapse, the mechanical transmission mechanism of the surrounding rock in the vertical direction is weakened, and the surrounding rock is the most stable.

scholarly journals Influence Factors of Vibration Response on Supporting-Thrusting System of Tunnel Boring Machine

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Yongbing Mei ◽  
Yimin Xia ◽  
Laikuang Lin ◽  
Yongliang Cheng ◽  
Cong Qian
Keyword(s):  
Influence Factors ◽  
Tunnel Boring Machine ◽  
Vertical Vibration ◽  
Surrounding Rock ◽  
Vibration Response ◽  
Main Beam ◽  
Support Pressure ◽  
Vibration Acceleration ◽  
Tunnel Boring ◽  
Input Load

A supporting-thrusting system is the main load-bearing component of a tunnel boring machine (TBM) and the centralization of vibration response under TBM working. This study combines the structure and working principle of the supporting-thrusting system. Based on the vibration theory and test results at a construction site, the main influence factors of the vibration response of the supporting-thrusting system are the main beam structure, the characteristic parameters of advance cylinder, and the support pressure to surrounding rock. Under the different influence factors, the vibration response of the supporting-thrusting system is calculated and analyzed via computer simulation. The results indicate that, under the equivalent input-load on the TBM and increase in the length of the front main beam, the vibration acceleration at the front area of the TBM increases. The change rate of vertical vibration will be maximum, while the vibration acceleration at the rear area of TBM decreases. When the structure size of the thrusting cylinder increases, the vibration acceleration on the main beam decreases and those of the gripper shoe and saddle frame increase. However, the response to the axis vibration is the most sensitive. As the horizontal support pressure to the surrounding rock increases, the vibration acceleration on supporting-thrusting system decreases. When the level of support pressure exceeds 1.6e4 kN, the vibration acceleration changes gradually. These results provide a reference for designing and operating TBM parameters.

scholarly journals Steel Plastic Geogrid Performance Testing and its Application in the Reduction of Spring Back of Shotcrete

2015 ◽  
Vol 9 (1) ◽  
pp. 223-229 ◽  
Author(s):  
Wang Qingbiao ◽  
Zhang Cong ◽  
LÜ Rongshan ◽  
Wen Xiaokang ◽  
Xu Lei ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Field Test ◽  
Influence Factors ◽  
Performance Testing ◽  
Surrounding Rock ◽  
Survey Method ◽  
Test Field ◽  
Sprayed Concrete ◽  
Engineering Research ◽  
Study Laboratory

In order to solve the problems of high springback of sprayed concrete and high dust concentration in the boltnetting support of underground engineering, research the mechanical properties of steel plastic geogrid and analyze the application of steel plastic geogrid replacing the metal net in the reduction of concrete through theoretical study, laboratory test, field test and contrast analysis, thus got the conclusion that: (1) Through the analysis of influence factors of the springback of surrounding rock supporting sprayed concrete, classification is carried on with the sampling survey method. The interaction between the metal net and concrete is the main factor to influence the springback of the concrete. (2) Study the performance differences of the steel plastic geogrid and the metal net. With the advantages of tensile strength, strong durability and injection connection, steel plastic geogrid has stronger applicability, safety and stability in adjusting the stress of the surrounding rock of the roadway and coordinating its deformation. (3)Through the tensile test and the deflection test, study the relationship between the tensile strength and external load under different aperture, thus establish the relation curve between the maximum deflection and load. (4) Through the roadway engineering construction and the analysis of the data of the field test, steel plastic geogrid can greatly reduce the springback of sprayed concrete which can guide the design and construction of underground bolt-netting support engineering.

Analysis of Influence Factors of Tunnel Surrounding Rock Stability and Researches of its Control Methods

2013 ◽  
Vol 438-439 ◽  
pp. 979-982
Author(s):  
Xian Kai Bao
Keyword(s):  
Influence Factors ◽  
Surrounding Rock ◽  
Control Methods ◽  
Engineering Construction ◽  
Entire Process ◽  
Rock Stability ◽  
Stability Of Surrounding Rock ◽  
Relationship Of ◽  
The Relationship ◽  
Non Destructive

This paper analyzes various factors about the surrounding rock stability in tunnel, on this basis, proposes control methods and ideas about the surrounding rock stability in tunnel, and discusses in detail the relationship of bolt working load and the surrounding rock stability. Using the approach of non-destructive monitoring bolts can be well monitor the surrounding rock stability of entire process. The result will provide great reference for research studies on stability of surrounding rock and the engineering construction.

scholarly journals Calculation Model and Decoupling Coefficient Sensitivity Study of Periphery Hole for Eccentric Decoupled Charge in Highway Tunnels

2018 ◽  
Vol 2018 ◽  
pp. 1-11
Author(s):  
Yuanqing Wang ◽  
Junfeng Liu
Keyword(s):  
Fractured Rock ◽  
Influence Factors ◽  
Small Diameter ◽  
Sensitivity Study ◽  
Calculation Model ◽  
Surrounding Rock ◽  
Fractured Rock Mass ◽  
Emulsion Explosive ◽  
Computational Theory ◽  
Decoupling Coefficient

On the basis of the eccentric decoupled charge form on site and borehole concentric decoupled computational theory, the calculation model of eccentric decoupling charge would be established in the present study. The calculation model takes into account the influence factors such as damage to the surrounding rock, air, and water decoupled media. Besides, based on the proposed calculation model, blasting effect of a small-diameter EJ-102 emulsion explosive is calculated by using ANSYS LS-DYNA. The influence of decoupling coefficient, different rock grade, and different RQD value on blasting effect is obtained by sensitivity analysis of the simulated parameters. Then the calculated results are compared with the empirical results. The blasting parameters of fractured rock mass are also optimized by numerical simulation.

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